Currently, in the field of countermeasuring manpad missiles, those missiles having seeker heads which detect infrared radiation from the engines of an aircraft, high intensity infrared sources such as lasers mounted on gimbals are utilized to provide radiation coded to spoof the incoming missile so that it moves away from its intended target. It is generally thought that 100 kW per steradian is what is required to jam an incoming missile attacking an aircraft comparable in size to a commercial airliner.
Such countermeasure devices, commonly referred to as directed infrared countermeasures or DIRCM devices are described in U.S. Pat. No. 7,378,626. In general these devices are mounted to the fuselage of an aircraft or helicopter and involve the directing of laser jamming radiation towards an incoming threat. These gimbals and their associated lasers are extremely costly to manufacture and install. Moreover, they require significant maintenance to assure that a laser beam emitted from the gimbal head illuminates the target.
Other methods of countermeasuring an incoming manpad missile include the use of flares which are ejected from the aircraft which act as decoys onto which an incoming missile will home. However once the flares are ejected, the aircraft or vehicle is unprotected, with flares oftentimes being of insufficient intensity to mask the infrared output of massive aircraft engines.
A third way of countermeasuring incoming threats is to utilize a high intensity infrared source or lamp about which a modulator is rotated. In one form the modulator utilizes apertured masks or reflectors. These jamming lamps have outputs which are inherently lower power than that associated with a laser. Moreover, the amount of power necessary to drive such lamps is considerable.
Both the lamp jammers and the DIRCM heads are exceedingly heavy, making their use on unmanned aerial vehicles such as drones problematic due to their weight alone.
In addition, these devices when attached to the outer surface of an airframe generate considerable aerodynamic drag. When deployed these devices significantly increase jet fuel usage and are therefore considered impractical at least from the commercial aviation point of view.
Both their initial installation cost of over a million dollars per aircraft and their maintenance-prone electromechanical nature makes the use of these jammers on commercial aircraft, or indeed on helicopters and smaller private aviation aircraft problematic.
In short, turreted DIRCMs have been cited as being too expensive to install and too costly in terms of fuel usage due to the fact that the DIRCM heads are constantly in the air stream.
There is therefore a need for an extremely simple, inexpensive and rapidly deployable method of protecting aircraft and other vehicles from attack by heat-seeking missiles by being able to project at least on the order of 100 kilowatts per steradian infrared energy onto the seeker head of an incoming missile.